Staff Rust Engineer (freelance contract, remote from the EU)

Location: Berlin (or remote)

A team is English-speaking

3-month freelance contract

Our client is a technology company that builds decentralized digital identity solutions. They believe that everyone has the right to own and control their data, and they are committed to creating a trusted digital credentials ecosystem that empowers businesses and individuals to securely exchange data and services across borders and industries.

They are in search of a solution-oriented Rust Software Engineer (Backend) with deep, demonstrable expertise and experience in Rust, to work on secure, scalable, and high-performance backend systems. You will be responsible for the continued enhancement and development of a multi-component platform, where your expert skills in designing, architecting, and building quality systems will intersect with your hands-on coding, performance testing, and integration experience.

Responsibilities:

• Build and deliver secure, high-quality features and improvements using Rust. Experience in TypeScript and Dart will set you above other applicants for this role
• Create standards-compliant world-class software systems and components, most of which will be open-sourced.
• Influence architectural direction while staying hands-on with development
• Design and implement solutions to complex, large-scale technical challenges
• Identify and drive the most critical improvements in product quality, security, and performance
• Guide the team to build well-tested, secure, and performant services
• Establish and refine best practices for high-scale distributed systems
• Collaborate closely with product, security, and engineering peers in a fast-paced, iterative environment

Requirements:

• Proven experience with performance optimization and a track record of diagnosing and preventing system bottlenecks
• Strong backend development skills with Rust as a core expertise
• Deep knowledge of TypeScript/Node.js; Dart experience strongly preferred. Familiarity with C# or Go is a plus
• Expertise in cloud computing (AWS) and cloud-native environments
• Proven track record in designing and deploying distributed systems using modern design patterns
• Skilled in technical documentation (C4 Model, ADRs) and clear communication of architectural decisions
• Strong advocate for privacy by design, security-first principles, and high-performance systems
• Expertise in applying asynchronous cryptography in production-grade products
• Experience with authorization/authentication domains; knowledge of identity, verifiable credentials, or secure data exchange is a strong plus
• Comfortable thriving in autonomous, fast-moving startup environments and collaborating across global teams